Speculation on her identity has been rife since late January, when news broke of the high-profile investigations into Ng, who is 46 years old, and ex-Singapore Civil Defence Force (SCDF) commissioner Peter Lim for alleged misconduct.

Ng, on the other hand, was on Tuesday morning charged with four counts of corruptly obtaining sexual gratification in the form of fellatio from Sue between June and December last year — twice while she was employed as a sales manager at Hitachi Data Systems Pte Ltd, and a further two times in December, when she had started work at Oracle Corporation Singapore.

Hitachi’s Singapore branch provides IT, security, and industrial products and services, among others, while Oracle provides software for e-business. Both are multinational corporations.

While it is not certain when exactly Sue was employed with Hitachi, she was working for them between June and November 2011, the period over which Ng’s first two offences were committed.

A spokesperson for Hitachi confirmed Sue’s employment with the company during that time, but said no one in the company was privy to her actions.

“Any alleged inappropriate behaviour attributed to our former employee during her time at HDS was undertaken without the knowledge of, or being condoned by, anyone at HDS,” she told Yahoo! Singapore in a statement.

Attempts to seek comment from representatives at Oracle all through Tuesday were stonewalled, with the company’s public relations executives declining to confirm whether or not Sue is still working there.

Rumours on her background continue to fly

Apart from details of her employment, conflicting rumours about Sue’s background continue to fly between local media and across internet forums, particularly in HardwareZone and SammyBoyForum.

The Straits Times previously reported that she was married and had given birth to a child in early 2011, but according to Lianhe Wanbao, she was divorced from her husband, whom the former said is a businessman who holds directorships in several companies.

She was described to have a tall and slim frame, with long, wavy hair. The English broadsheet also reported that Ng knew Sue for more than three years, and had been close to her since early 2009.

Internet users on SammyBoyForum posted screengrabs of what was believed to be Sue’s LinkedIn profile in January, which detailed her employment and education history.

This included spending about six years at IBM Singapore as an advisory sales specialist, after studying at Curtin University of Technology and Singapore Polytechnic. The Straits Timespreviously reported that Sue attended a local polytechnic as well as an Australian university before entering sales in the IT industry. The LinkedIn profile, as well as a Facebook profile believed to belong to her, was soon taken down.

No longer servicing CNB accounts: MHA

Separately, the Ministry of Home Affairs (MHA) confirmed that Sue is no longer involved in servicing accounts that either of her employers had or have with CNB.

A spokesperson said, however, that as Ng’s case is before the courts, the ministry is unable to confirm whether or not the contracts and tenders Ng and Sue were separately or directly involved in have been suspended or under review.

“(The ministry) is not able to provide any information which may potentially be the subject of the charges against Mr Ng Boon Gay,” he explained.

In the meantime, Ng’s lawyers said they will be writing in to the public prosecutor’s office to seek clarification on the four charges, specifically on how the acts of fellatio advanced the business interests of Hitachi and Oracle, as well as what the interests themselves were.

It is not known at this stage whether or not Sue will be required to testify should the case proceed to trial, as Ng’s defence counsel made clear on Tuesday that he will be challenging all four of his charges.